Training Design for Precoded BICM-MIMO Systems in Block-Fading Channels
In order to improve bandwidth efficiency and error performance, a new training scheme is proposed for Bit-Interleaved-Coded Modulation in Multiple-Input Multiple-Output (BICM-MIMO) systems. Typically, in a block-fading channel, the training overhead used for obtaining channel knowledge is proportional to a power of 2 of the number of transmit antennas. However, this overhead can be reduced by embedding pilot symbols within data symbols before precoding. The values, positions, and the number of pilot symbols are found by minimizing the Cramer-Rao bound on the channel estimation error.